Retrospective Surveillance of Wastewater To Examine Seasonal Dynamics of Enterovirus Infections

Abstract

Enteroviruses are RNA viruses that are responsible for both mild gastroenteritis and mild respiratory illnesses as well as debilitating diseases such as meningitis and myocarditis. The disease burden of enteroviruses in the United States is difficult to assess because most infections are not recorded. Since infected individuals shed enterovirus in feces and urine, surveillance of municipal wastewater can reveal the diversity of enteroviruses circulating in human populations. Therefore, monthly municipal wastewater samples were collected for 1 year and enteroviruses were quantified by reverse transcriptase quantitative PCR and identified by next-generation, high-throughput sequencing. Enterovirus concentrations ranged from 3.8 to 5.9 log equivalent copies/liter in monthly samples. From the mean monthly concentration, it can be estimated that 2.8% of the contributing population was shedding enterovirus daily. Sequence analysis showed that and alternate in predominance, with comprising over 80% of the reads during the summer and fall months and accounting for >45% of the reads in spring. was observed throughout the year, while was present intermittently. Principal-component analysis further supported the date corresponding to enterovirus seasonal trends as CVA6 () was predominant in the spring months; CVB3, CVB5, and E9 () were predominant in the summer and fall months; and CVA1, CVA19, and CVA22 () and EV97 () were predominant in winter. Rhinoviruses were also observed. Wastewater monitoring of human enterovirus provided improved insight into the seasonal patterns of enteroviruses circulating in communities and can contribute to understanding of enterovirus disease burden. Enterovirus infections are often not tracked or reported to health officials. This makes it hard to know how many people in a community are infected with these viruses at any given time. Here, we explored enterovirus in municipal wastewater to look at this issue. We show that enteroviruses are present year-round in municipal wastewater at levels of up to 800,000 genomic copies per liter. We estimate that, on average, 2.8% of the people contributing to the wastewater shed enterovirus daily. Sequence analysis of the viral capsid protein 4 gene shows that 8 enterovirus types are key drivers of seasonal trends. Populations of members peak in the spring, while types are most prevalent during the summer and fall months and members influence the winter months. was observed sporadically and did not influence seasonal trends.

Detection of Enterovirus D68 in wastewater samples from the United Kingdom during outbreaks reported globally between 2015 and 2018

“…Nevertheless, EV-D68 was frequently detected in wastewater samples during reported outbreaks despite the fact that the virus is rarely found in stools from clinical cases (Barnadas et al 2017, Van Leer-Buter et al 2016). Although the presence of EV-D68 in sewage has been reported before (Benschop et al 2017, Brinkman et al 2017, Weil et al 2017), our finding was unexpected and suggests that EV-D68 might replicate in the gut more commonly than it is thought, perhaps during the initial stages of infection before respiratory symptoms develop and samples are collected for analysis. Although unlikely, the possibility that EV-D68 present in human respiratory fluids could reach the sewage system through washing, showering, etc.…”

Environmental Surveillance Reveals Complex Enterovirus Circulation Patterns in Human Populations

“…EV-D strains (all from serotype EV-D68) were only found in sewage samples from the United Kingdom. Studies using a variety of cell lines or direct molecular typing have shown the prevalence of EV-B strains in sewage in Europe and the United States (typically >75% of all EVs), with the occasional upsurge of EV-A and EV-D serotypes in recent years [ 15 , 21 ]. Interestingly, a recent study in Scotland identified a high quantity of EV-C strains in sewage samples (95 amplicons from 353 cloned EV sequences, 26.9%) [ 14 ].…”

“…Next-generation sequencing (NGS) metagenomics and target-specific techniques have been described by us and others to detect EV strains in clinical and environmental samples [ 17–20 ]. However, the output from NGS analysis of uncultured EV strains present in sewage has been so far mostly restricted to information on the EV species or, in very few cases, the EV serotype composition [ 21 ], with insufficient nucleotide sequence information down to the genotype and strain level.…”

Efficacy of Inactivation of Human Enteroviruses by Dual-Wavelength Germicidal Ultraviolet (UV-C) Light Emitting Diodes (LEDs)

“…While most infected people with non-polio enteroviruses have mild illness, these viruses can cause infections in infants and other immunocompromised individuals with serious complications [3]. Human enteroviruses are often detected in wastewater effluents [5][6][7]. Since 2003, these viruses have been listed on the United States Environmental Protection Agency (USEPA)'s Contaminant Candidate Water 2019, 11, 1131 2 of 8 List (CCL) as waterborne pathogens that could warrant inclusion in future regulations under the Safe Drinking Water Act [8].…”